The expression √5−√3√5+√3 when simplified reduces to a-b√15.
Then a + b is __________.
5
In √5−√3√5+√3, the denominator has to be rationalised for simplification. So ,
√5−√3√5+√3×√5−√3√5−√3
=(√5−√3)2√52−√32
=12[(√5)2+(√3)2−2√15]
=4−√15
So, a=4 and b=1.
∴a + b = 4 + 1 = 5